Engine Management System

Abstract

To provide an engine control system which can inhibit deterioration of an engine oil, and to provide an engine control method, and an engine control program.SOLUTION: An engine control system 2 according to the disclosure includes an oil temperature sensor 21 and a wastegate valve control unit 22. The oil temperature sensor 21 detects a temperature of an engine oil. The wastegate valve control unit 22 controls opening / closing of a wastegate valve WGV based on the temperature of the engine oil detected by the oil temperature sensor 21. More specifically, the wastegate valve control unit 22 provides control so as to open the wastegate valve WGV when the temperature of the engine oil detected by the oil temperature sensor 21 is a predetermined threshold value or lower.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to an engine control system, an engine control method, and an engine control program. [Background technology]

[0002] Patent Document 1 describes an engine control device that controls an on-off valve that opens and closes a bypass passage that bypasses a turbocharger provided in an exhaust passage of the engine. The engine control device described in Patent Document 1 forcibly closes the on-off valve when a state in which there is a high possibility that the vehicle will be accelerated is detected.

[0003] The on-off valve described in Patent Document 1 is generally called a wastegate valve, and will be referred to as a wastegate valve hereinafter in this specification. When the wastegate valve is closed, the turbocharger is operated. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2008-014289 A Summary of the Invention [Problem to be solved by the invention]

[0005] The engine control device described in Patent Document 1 forcibly closes the wastegate valve when there is a high possibility that the vehicle will accelerate, even before the engine is required to generate torque that requires the turbocharger to operate. With this configuration, the turbocharger is operated for a longer period of time.

[0006] As the operating time of the turbocharger increases, deterioration of the engine oil is accelerated. Therefore, the engine control device described in Patent Document 1 has a problem in that the deterioration of the engine oil becomes faster.

[0007] The present disclosure has been made to solve such problems, and aims to provide an engine control system, an engine control method, and an engine control program that are capable of suppressing deterioration of engine oil. [Means for solving the problem]

[0008] An engine control system according to an embodiment of the present disclosure includes: an oil temperature sensor for detecting the temperature of engine oil; a wastegate valve control unit that controls opening and closing of a wastegate valve based on the temperature of the engine oil detected by the oil temperature sensor, When the temperature of the engine oil detected by the oil temperature sensor is equal to or lower than a predetermined threshold value, the wastegate valve control unit controls the wastegate valve to open. An engine control system.

[0009] The lower the temperature of engine oil, the more easily it absorbs oil-degrading substances. Therefore, if the wastegate valve is configured to open when the engine oil level is low, the amount of oil-degrading substances absorbed by the engine oil can be reduced, and as a result, the deterioration of the engine oil can be suppressed.

[0010] The engine control system is The vehicle further includes a required torque calculation unit that calculates a required torque for the engine based on an amount of depression of an accelerator pedal, When the required torque is equal to or greater than a predetermined threshold, the wastegate valve control unit may perform control to close the wastegate valve regardless of the temperature of the engine oil. Such a configuration improves engine responsiveness.

[0011] The engine control system is A water temperature sensor is further provided for detecting the temperature of engine cooling water. When the temperature of the cooling water detected by the water temperature sensor is equal to or lower than a predetermined threshold value, the wastegate valve control unit may perform control to open the wastegate valve. Since there is a correlation between the temperature of the engine coolant and the temperature of the engine oil, this configuration can further suppress deterioration of the engine oil.

[0012] An engine control method according to an aspect of the present disclosure includes: Detects engine oil temperature, The engine oil temperature sensor detects the temperature of the engine oil, and controls the opening and closing of the wastegate valve based on the detected temperature. When the temperature of the engine oil detected by the oil temperature sensor is equal to or lower than a predetermined threshold value, the wastegate valve is controlled to be opened. An engine control method.

[0013] An engine control program according to an embodiment of the present disclosure includes: Detects engine oil temperature, The engine oil temperature sensor detects the temperature of the engine oil, and controls the opening and closing of the wastegate valve based on the detected temperature. When the temperature of the engine oil detected by the oil temperature sensor is equal to or lower than a predetermined threshold value, the wastegate valve is controlled to be opened. The engine control program. Effect of the Invention

[0014] The present disclosure makes it possible to provide an engine control system, an engine control method, and an engine control program capable of suppressing deterioration of engine oil. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic diagram showing a configuration of an engine system equipped with a turbocharger. [Diagram 2]1 is a block diagram showing a configuration of an engine control system according to a first embodiment. [Diagram 3] 4 is a flowchart showing the operation of the engine control system according to the first embodiment. [Figure 4] FIG. 5 is a block diagram showing a configuration of an engine control system according to a second embodiment. [Diagram 5] 7 is a flowchart showing the operation of an engine control system according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] (Mechanism of problem occurrence) <Engine system configuration> The mechanism by which the problem occurs in the present disclosure will be described in detail. First, the configuration of the engine system in which the problem occurs will be described in detail. Fig. 1 is a schematic diagram showing the configuration of an engine system equipped with a turbocharger.

[0017] The engine system 1 mainly comprises an engine E, a throttle TH, a blow-by gas reduction (PCV, Positive Crankcase Ventilation) valve PCV, an intake manifold IM, an exhaust manifold EM, an intake passage E1, an exhaust passage E2, a blow-by gas exhaust passage E3, a turbocharger TC, a bypass passage BP, and a wastegate valve WGV.

[0018] The engine E is an internal combustion engine that is driven by fuel such as gasoline. The engine E mixes air supplied from an intake manifold IM with the fuel, burns the mixture, and outputs driving force. The engine E discharges exhaust gas generated by the combustion into an exhaust passage E2. The engine E also discharges blow-by gas into a blow-by gas exhaust passage E3.

[0019] However, the blow-by gas referred to here refers to unburned gas and air-fuel mixture that leaks into the crankcase through the gap between the cylinder and piston of engine E. The blow-by gas discharged from the engine E passes through a blow-by gas exhaust passage E3 and merges with the air passing through the intake manifold IM. Then, the blow-by gas is supplied to the engine E again.

[0020] Air is supplied to the engine system 1 through the intake passage E1 and the intake manifold IM. More specifically, the air supplied from the intake passage E1 flows through the turbocharger system TC to the intake manifold IM and is supplied to the engine E. The air supplied through the intake manifold IM includes blow-by gas supplied from the blow-by gas exhaust passage E3.

[0021] Exhaust gas discharged from the engine system 1 is discharged from an exhaust passage E2. More specifically, exhaust gas discharged from the engine E is discharged from an exhaust manifold EM via a turbocharger TC or a bypass passage BP.

[0022] The blow-by gas return valve PCV is a valve that prevents air flowing through the intake manifold IM from flowing into the blow-by gas exhaust passage E3. In other words, the blow-by gas return valve PCV is an air valve that limits the direction of gas flow to the direction from the blow-by gas exhaust passage E3 to the intake manifold IM.

[0023] The throttle TH is a valve that adjusts the amount of air supplied to the engine E. More specifically, the amount of air supplied to the engine E is adjusted by controlling the opening of the throttle TH. The opening of the throttle TH is controlled so that the more torque required of the engine, the more air is supplied to the engine E.

[0024] The turbocharger TC compresses air supplied from an intake passage E1 and supplies the compressed air to the engine E. The turbocharger TC discharges exhaust gas discharged from the engine E into an exhaust manifold EM. The turbocharger TC includes a turbine T, a compressor C, and a shaft SH.

[0025] Exhaust gas discharged from the engine E is supplied to the turbine T via an exhaust path E2. The turbine T is rotated by the supplied exhaust gas. The turbine T and the compressor C are connected via a shaft SH. Therefore, the rotation of the turbine T drives the rotation of the compressor C. The exhaust gas that passes through the turbine T is discharged to the exhaust manifold EM.

[0026] The compressor C, which is rotationally driven by the turbine T, compresses air supplied from an intake passage E1. The compressor C then supplies the compressed air to the engine E via an intake manifold IM. Supplying compressed air to the engine E in this manner increases the amount of torque that the engine E can output.

[0027] The bypass path BP bypasses the exhaust path E2 and the exhaust manifold EM. In other words, the bypass path BP is a passage for allowing the exhaust gas discharged from the engine E to flow to the exhaust manifold EM without passing through the turbine T. The amount of exhaust gas flowing through the bypass path BP is adjusted by the wastegate valve WGV.

[0028] The wastegate valve WGV adjusts the amount of exhaust gas flowing into the bypass passage BP. When the wastegate valve WGV is closed, exhaust gas does not flow through the bypass passage BP. In this case, the exhaust gas discharged from the exhaust passage E2 is discharged through the turbine T. Therefore, the turbine T and the compressor C rotate, and as a result, compressed air is supplied to the engine E.

[0029] On the other hand, when the wastegate valve WGV is open, exhaust gas flows through the bypass passage BP. In this case, almost no exhaust gas discharged from the exhaust passage E2 flows through the turbine T. Therefore, the turbine T and the compressor C do not rotate, and as a result, uncompressed air is supplied to the engine E.

[0030] In other words, when the wastegate valve WGV is closed, the turbocharger TC operates, and when the wastegate valve WGV is open, the turbocharger TC does not operate.

[0031] <Engine oil deterioration> In the following, the case where the wastegate valve WGV is closed, i.e., the turbocharger TC is operating, will be considered.

[0032] When the turbocharger TC is operating, the exhaust gas is discharged through the turbine T, so the pressure of the gas flowing through the exhaust passage E2 increases. When the pressure in the exhaust passage increases, the amount of work that the engine E does on the gas increases accordingly, so the amount of torque that the engine E can output by taking in air per unit amount decreases.

[0033] Therefore, if the amount of torque required of the engine E is the same, a larger amount of air needs to be supplied to the engine E when the turbocharger TC is operating.

[0034] When a larger amount of air is supplied to the engine E, the amount of air flowing through the intake manifold IM increases. When the amount of air flowing through the intake manifold IM increases, the air pressure inside the intake manifold IM increases.

[0035] Incidentally, when the air pressure in the intake manifold IM increases, the amount of blow-by gas discharged decreases. In other words, when the air pressure in the intake manifold IM increases, the ventilation rate of the blow-by gas in the engine E decreases.

[0036] Therefore, when the turbocharger TC is operating, the ventilation rate of the blow-by gas in the engine E decreases. As a result, the concentration of the blow-by gas in the engine E increases.

[0037] The blow-by gas contains substances that deteriorate the engine oil, such as nitrogen oxides, etc. Therefore, when the concentration of the blow-by gas in the engine E increases, the deterioration of the engine oil is accelerated. In other words, when the wastegate valve WGV is closed, the problem of accelerated deterioration of the engine oil occurs.

[0038] <Overview of the embodiment> Therefore, in the engine control system according to the present disclosure, in order to suppress deterioration of the engine oil, the wastegate valve is opened when the temperature of the engine oil is equal to or lower than a predetermined threshold value.

[0039] (First embodiment) <Engine control system configuration> Hereinafter, a first embodiment of the present disclosure will be described in detail with reference to the drawings. First, the configuration of the engine control system according to the present embodiment will be described in detail. Fig. 2 is a block diagram for explaining the configuration of the engine control system according to the first embodiment. In the following description, Fig. 1 will be referred to as appropriate.

[0040] An engine control system 2 according to this embodiment controls the engine system 1 shown in Fig. 1. The engine control system 2 acquires the temperature of engine oil in the engine E. Then, based on the acquired engine oil temperature, it controls the opening and closing of the wastegate valve WGV. The engine control system 2 according to this embodiment includes an oil temperature sensor 21 and a wastegate valve control unit 22.

[0041] The oil temperature sensor 21 is a temperature sensor attached to the engine E, and detects the temperature of the engine oil in the engine E. The oil temperature sensor 21 outputs the obtained temperature to the wastegate valve control unit 22.

[0042] The wastegate valve control unit 22 obtains the temperature of the engine oil in the engine E from the oil temperature sensor 21. Then, based on the temperature of the engine oil detected by the oil temperature sensor 21, the wastegate valve control unit 22 controls the opening and closing of the wastegate valve WGV.

[0043] More specifically, when the temperature of the engine oil detected by the oil temperature sensor 21 is equal to or lower than a predetermined threshold value, the wastegate valve control unit 22 controls the wastegate valve WGV to open.

[0044] When the temperature of the engine oil detected by the oil temperature sensor 21 is not equal to or lower than a predetermined threshold value, the wastegate valve control unit 22 may control the wastegate valve WGV to open or close.

[0045] When the temperature of the engine oil detected by the oil temperature sensor 21 is not below a predetermined threshold, the wastegate valve control unit 22 may control the opening and closing of the wastegate valve WGV based on, for example, the required torque for the engine E and the opening degree of the throttle TH.

[0046] <Engine control system operation> Next, the operation of the engine control system, i.e., the engine control method according to the first embodiment, will be described in detail. Fig. 3 is a flowchart for explaining the operation of the engine control system according to the first embodiment. In the following description, Fig. 1 and Fig. 2 will be referred to as appropriate.

[0047] First, the oil temperature sensor 21 detects the oil temperature (step ST101). The detected oil temperature is output to the wastegate valve control unit 22. Next, the wastegate valve control unit 22 determines whether or not the oil temperature is equal to or lower than a predetermined threshold value (step ST102).

[0048] If the oil temperature is equal to or lower than the predetermined threshold value (YES in step ST102), the wastegate valve control unit 22 opens the wastegate valve WGV (step ST103), and the engine control system 2 ends the series of operations.

[0049] If the oil temperature is not equal to or lower than the predetermined threshold value (NO in step ST102), the wastegate valve control unit 22 opens and closes the wastegate valve WGV based on the required torque for the engine and the throttle opening (step ST104), and the engine control system 2 ends the series of operations.

[0050] The engine control system 2 according to this embodiment may repeatedly execute the series of operations shown in the flowchart of Fig. 3. Moreover, the engine control system 2 may repeatedly execute the series of operations and end the repetition of the series of operations when step ST104 is executed.

[0051] As described above, the engine control system 2 according to this embodiment detects the temperature of the engine oil. Then, the engine control system 2 controls the opening and closing of the wastegate valve WGV based on the detected temperature.

[0052] According to this configuration, when the temperature of the engine oil is low, that is, when the engine oil is in a state where it is easy to deteriorate, the turbocharger is prevented from operating. As a result, the engine control system 2 can suppress deterioration of the engine oil.

[0053] Furthermore, when the engine oil temperature is low, the engine oil may not be sufficiently distributed throughout the engine. Therefore, by not operating the turbocharger when the engine oil temperature is low, the engine control system 2 can also suppress engine deterioration.

[0054] Second Embodiment <Engine control system configuration> Hereinafter, the second embodiment of the present disclosure will be described in detail with reference to the drawings. First, the configuration of the engine control system according to the present embodiment will be described in detail. Fig. 4 is a block diagram for explaining the configuration of the engine control system according to the second embodiment. In the following description, Fig. 1 will be referred to as appropriate.

[0055] The engine control system 2 according to this embodiment is an application example of the engine control system 2 according to the first embodiment. The engine control system 2 according to this embodiment differs from the engine control system 2 according to the first embodiment in that the engine control system 2 according to this embodiment includes a required torque calculation unit 23 and a throttle control unit 24. The preferred embodiment of the oil temperature sensor 21 is the same as that in the first embodiment.

[0056] In the engine control system 2 according to this embodiment, the wastegate valve control section 22, the required torque calculation section 23, and the throttle control section 24 are realized as functional blocks of the engine control unit ECU.

[0057] The engine control unit ECU includes a calculation unit such as a CPU (Central Processing Unit) (not shown) and a storage unit such as a RAM (Random Access Memory) or a ROM (Read Only Memory) that stores programs and data for controlling the engine system 1. In other words, the engine control unit ECU functions as a computer and controls the engine system 1 based on the programs.

[0058] 4 can be realized in terms of hardware by the CPU, storage unit, other circuits, etc., and in terms of software by a program for controlling the engine system 1 stored in the storage unit. In other words, the engine system 1 can be realized in various forms by hardware, software, or a combination of both.

[0059] The program includes a set of instructions (or software code) for making the computer perform one or more functions described in the embodiment when the program is read into the computer. The program may be stored in a non-transitory computer-readable medium or a tangible storage medium. By way of example and not limitation, the computer-readable medium or tangible storage medium includes random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drive (SSD) or other memory technology, CD-ROM, digital versatile disc (DVD), Blu-ray (registered trademark) disk or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage device. The program may be transmitted on a transitory computer-readable medium or communication medium. By way of example and not limitation, the transitory computer-readable medium or communication medium includes electrical, optical, acoustic, or other forms of propagating signals.

[0060] The required torque calculation unit 23 acquires the depression amount of the accelerator pedal AC of the vehicle. Then, based on the acquired depression amount of the accelerator pedal AC, it calculates a required torque for the engine E. The required torque calculation unit 23 outputs the calculated required torque to the wastegate valve control unit 22 and the throttle control unit 24.

[0061] The throttle control unit 24 controls the opening degree of the throttle TH, i.e., the amount of air supplied to the engine E. More specifically, the throttle control unit 24 controls the amount of air supplied to the engine E based on the required torque acquired from the required torque calculation unit 23.

[0062] The throttle control unit 24 controls the opening degree of the throttle TH so that the amount of air supplied to the engine E increases as the required torque acquired from the required torque calculation unit 23 increases. The greater the throttle opening, the more air the throttle TH supplies to the engine E.

[0063] The throttle control unit 24 outputs a control signal indicating the opening degree of the throttle TH to the throttle TH. The throttle control unit 24 also outputs a control signal indicating the opening degree of the throttle TH to the wastegate valve control unit 22.

[0064] The wastegate valve control unit 22 according to this embodiment first determines whether or not the required torque for the engine E, acquired from the required torque calculation unit 23, is equal to or greater than a predetermined threshold value.

[0065] When the torque required for the engine E is equal to or greater than a predetermined threshold value, the wastegate valve control unit 22 controls the wastegate valve WGV to close, regardless of the temperature of the engine oil.

[0066] With this configuration, even if the driver requests a torque that cannot be output without using a turbocharger, the requested torque can be output, resulting in improved engine response and improved vehicle operability.

[0067] When the torque required for the engine E is equal to or greater than a predetermined threshold, the wastegate valve control unit 22 acquires the engine oil temperature and the throttle opening degree, and controls the opening and closing of the wastegate valve WGV based on the acquired oil temperature and throttle opening degree.

[0068] More specifically, the wastegate valve control unit 22 controls the wastegate valve WGV to open when the temperature of the engine oil is equal to or lower than a predetermined threshold value, similarly to the first embodiment.

[0069] When the temperature of the engine oil is not equal to or lower than the predetermined threshold, the wastegate valve control unit 22 determines whether or not the throttle opening is equal to or higher than the predetermined threshold. When the throttle opening is equal to or greater than a predetermined threshold value, the wastegate valve control unit 22 controls the wastegate valve WGV to close. Furthermore, when the throttle opening is not equal to or greater than a predetermined threshold, the wastegate valve control unit 22 controls the wastegate valve WGV to open.

[0070] According to this configuration, compression of the air to be supplied to the engine E can be started before a torque that cannot be output without operating the turbocharger is required, thereby improving the responsiveness of the engine.

[0071] <Engine control system operation> Next, the operation of the engine control system, that is, the engine control method according to the second embodiment will be described in detail. Fig. 5 is a flowchart for explaining the operation of the engine control system according to the first embodiment. In the following description, Fig. 1 and Fig. 4 will be referred to as appropriate.

[0072] First, the required torque calculation unit obtains the accelerator depression amount (step ST201), and calculates the required torque (step ST202). The calculated required torque is output to the wastegate valve control unit 22. Next, the wastegate valve control unit 22 determines whether or not the required torque is equal to or greater than a predetermined threshold value (step ST203).

[0073] If the required torque is equal to or greater than the predetermined threshold value (YES in step ST203), the wastegate valve control unit 22 closes the wastegate valve (step ST209), and the engine control system 2 ends the series of operations.

[0074] If the required torque is not equal to or greater than the predetermined threshold value (NO in step ST203), the wastegate valve control unit 22 acquires the throttle opening degree from the throttle control unit 24 (step ST204) and acquires the oil temperature from the oil temperature sensor 21 (step ST205). However, the order of steps ST204 and ST205 may be reversed, or steps ST204 and ST205 may be performed in parallel.

[0075] Next, the wastegate valve control unit 22 determines whether the oil temperature is equal to or lower than a predetermined threshold value (step ST206). If the oil temperature is equal to or lower than the predetermined threshold value (YES in step ST206), the wastegate valve control unit 22 opens the wastegate valve (step ST207), and the engine control system 2 ends the series of operations.

[0076] If the oil temperature is not equal to or lower than the predetermined threshold value (NO in step ST206), the wastegate valve control unit 22 determines whether or not the throttle opening is equal to or higher than a predetermined threshold value (step ST208).

[0077] If the throttle opening is equal to or greater than the predetermined threshold value (YES in step ST208), the wastegate valve control unit 22 closes the wastegate valve (step ST209), and the engine control system 2 ends the series of operations.

[0078] If the throttle opening is equal to or greater than the predetermined threshold value (NO in step ST209), the wastegate valve control unit 22 opens the wastegate valve (step ST207), and the engine control system 2 ends the series of operations. The engine control system 2 according to this embodiment may repeatedly execute the series of operations shown in the flowchart of FIG.

[0079] As described above, the engine control system 2 according to this embodiment opens the wastegate valve and does not operate the turbocharger when the temperature of the engine oil is equal to or lower than a predetermined threshold value. As a result, the engine control system 2 can suppress deterioration of the engine oil. Furthermore, the engine control system 2 according to this embodiment operates the turbocharger when the driver requests a torque large enough to operate the turbocharger, even if the engine oil temperature is below a predetermined threshold value. With this configuration, the engine control system 2 can improve the responsiveness of the engine while suppressing deterioration of the engine oil.

[0080] (Other embodiments) The engine control system according to the present disclosure may further include a water temperature sensor that detects the temperature of engine coolant. When the temperature of the coolant detected by the water temperature sensor is equal to or lower than a predetermined threshold value, the wastegate valve control unit may perform control to open the wastegate valve. Since there is a correlation between the temperature of the engine coolant and the temperature of the engine oil, the above-described configuration can further suppress deterioration of the engine oil.

[0081] While the present invention has been described above with reference to the above-described embodiment, the present invention is not limited to the configuration of the above-described embodiment, and naturally includes various modifications, alterations, and combinations that may be made by a person skilled in the art within the scope of the invention as defined in the claims of the present application. [Explanation of symbols]

[0082] 2. Engine Management System 21 Oil temperature sensor 22 Wastegate valve control section 23 Required torque calculation section 24 Throttle control unit E-Engine WGV Wastegate Valve TH Throttle ECU Engine Control Unit

Claims

[Claim 1] An engine control system for controlling an engine system that supplies blow-by gas to an engine, an oil temperature sensor for detecting the temperature of engine oil; a required torque calculation unit that calculates a required torque for the engine based on an amount of depression of an accelerator; a wastegate valve control unit that controls opening and closing of a wastegate valve based on the engine oil temperature detected by the oil temperature sensor, the required torque calculated by the required torque calculation unit, and a throttle opening degree, The wastegate valve control unit is If the required torque is equal to or greater than a predetermined threshold, closing the wastegate valve regardless of the engine oil temperature; If the required torque is below a predetermined threshold, determining whether the temperature of the engine oil is equal to or lower than a predetermined threshold; opening the wastegate valve when the engine oil temperature is below a predetermined threshold; If the engine oil temperature exceeds a predetermined threshold, determining whether the throttle opening is equal to or greater than a predetermined threshold; When the throttle opening is equal to or greater than a predetermined threshold, the wastegate valve is closed, and when the throttle opening is below the predetermined threshold, the wastegate valve is opened. Engine control system.

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